1. Field of the Invention
The present invention relates in general to conductive material, and more particularly to contact pads for the fabrication of semiconductor devices and circuits.
2. Background
During the fabrication process of a semiconductor device, a manufacturer typically performs tests at various stages of the process to ensure that the device is functioning properly. While these tests are being performed, sensors or probes are usually brought into contact with pads on the surface of the semiconductor device. Unfortunately, bringing probes into contact with the pads frequently scratches the pads.
These scratches can contaminate the fabrication environment by introducing particles of the pad material into the environment. Furthermore, the scratches can reduce the reliability of further testing by damaging the contact area between the probes and the pads. If the fabrication environment becomes contaminated or the testing procedures become unreliable, then the fabrication process may yield devices that do not function properly.
To function properly, conventional pads exhibit certain properties, such as low resistivity and good adhesion to the semiconductor substrate. Unfortunately, materials having these properties usually lack sufficient hardness to resist scratching when brought into contact with test probes. Conversely, materials having sufficient hardness to resist scratching generally exhibit high resistivity or poor adhesion to the semiconductor substrate.
A conductive composition of titanium boronitride (TiBxNy) is disclosed for use as a conductive material. For example, the titanium boronitride is used to construct contact pads such as inline pads or backend pads. The titanium boronitride can also be used to construct sensors such as probes. Advantages of embodiments of the titanium boronitride include reduced scratching, increased hardness, finer granularity, thermal stability, good adhesion, and low bulk resistivity. Exemplary methods of creating the titanium boronitride include a sputtering process and a plasma anneal process.
In one embodiment of the invention, a test pad comprises a first metal layer and a first dielectric layer above the metal layer. The test pad further comprises a plug in the first dielectric layer, the plug in communication with the metal layer, and a TiBxNy layer above the first dielectric layer, the TiBxNy layer in communication with the plug.
In another embodiment, a test pad comprises a substrate and a first dielectric layer on the substrate, the first dielectric layer having a via to the substrate. The test pad further comprises a TiBxNy layer in at least a portion of the via, the TiBxNy layer in communication with the substrate.
In another embodiment, an integrated circuit comprises a TiBxNy conductor. In yet another embodiment, a contact pad comprises TiBxNy. In still another embodiment, a sensor comprises a TiBxNy surface. In yet another embodiment, a testing system comprises test circuitry, a probe in communication with the test circuitry, and a test pad in communication with the probe, wherein at least a portion of the test pad comprises TiBxNy. In an additional embodiment, a testing system comprises test circuitry and a sensor in communication with the test circuitry, wherein at least a portion of the sensor comprises TiBxNy.
In one embodiment, a method comprises connecting a TiBxNy surface of a sensor to a contact on a semiconductor device. In another embodiment, a method comprises of contacting a sensor to a TiBxNy surface on a contact pad.
In another embodiment, a method of forming an integrated circuit comprises depositing TiBxNy on a substrate. In yet another embodiment, a method of forming a conductive element in an integrated circuit comprises forming a plurality of devices in a semiconductor substrate. The method also comprises interconnecting the devices to form a circuit having a plurality of circuit nodes. The method further comprises depositing a pad layer in electrical contact with at least one of the circuit nodes. The pad layer comprises at least boron and nitrogen.
In another embodiment, a test pad comprises a substrate, a metal layer and a first dielectric layer above the metal layer. The test pad further comprises a plug in the first dielectric layer, the plug in communication with the metal layer. The test pad also comprises an aluminum layer in communication with the plug wherein the alumninum layer is above the plug. In addition, the test pad comprises a TiBxNy layer in communication with the aluminum layer wherein the TiBxNy layer is above the aluminum layer. The TiBxNy has an x-factor between about 0.5 and 2 and a y-factor between about 0.2 and 2. The test pad further comprises a second dielectric layer above the TiBxNy layer wherein the second dielectric layer is etched to expose the TiBxNy layer.